I am embarrassed because of my small chest size?

B cup is average for a petite girl. If you're rather tall, I can see how the proportions might be less than desirable, but either way it's honestly not a huge deal. For starters, there are plenty of guys (including me) who actually prefer nicely shaped smaller breasts rather than saggier big ones. Second, even guys who like 'em big won't make a fuss about it. At the end of the day, boobs are boobs, and that's really all there is to it.